Syringe



(No Model.)

P. B. LASKEY. SYRINGE.

No. 530,187. Patented Dec. 4, 1894.

IITED STATES PATEN Fries.

PHILIP B. LASKEY, OF MARBLEHEAD, MASSACHUSETTS.

SYRING E.

SPECIFICATION forming part of LettersPatent No. 530,187, dated December4, 1894.

Application filed September 15, 1894. Serial No. 5Z3| N model-l To aZZwhom it may concern:

Be it known that I, PHILIP BrLASKEY, a citizen of the United States,residing at'Marblehead, in the county of Essex andState ofMassachusetts, have invented certain new and useful Improvements inSyringes, of which the following is a specification, reference being hadtherein to the accompanying drawings. 1 I

In the use of hypodermic syringes by dentists, for the purpose ofinsertinga local an assthetic into the gums of patients beforeperforming an operation, considerable difficulty is experienced inforcing the liquid into the tissue composing the gums owing to thedensity thereof which resiststhe entrance of the liquid. In the use ofsyringes for the purpose stated it'is necessary that the piston shouldbe packed very tight to prevent leakage of the liquid, and when thepistons are thus tightly packed ittakes considerable force to overcomethe friction in operating them, leaving little power for the injectingforce.

My invention has for its object to provide a hypodermic syringe for'dentistsnse which will be free from the objections noted, and which isprovided with a resistance handle with which is connected a lever foroperating the piston of the syringe, the lever being so arranged as tosecure as much power as may be required in forcing the piston, intheinjecting operation.

Another object of my invention is to provide the needle end of thesyringe with a porous disk or plug to serve as a filter for the liquid,and thus prevent any foreign matter from entering the liquid passage inthe needle, said liquid passage being extremely small, and thus beingliable to be clogged or stopped up by very small particles of solidmatter.

In the accompanying drawings Figure 1 is a side view of a syringeembodying one form of my invention, and Fig. 2 is a section of the same.Fig. 3 is a detail plan view to show the operating lever, the piston rodbeing in section. Fig. 4 is a sectional viewof a somewhat simpler formof my invention than that shown in Figs. 1 and 2.

A denotes the body of the syringe, the same being preferably provided atits needle end with a removable cap a, in which is inclosed a rubberpacking ring 0. in which is inserted a small disk or plug 5 of felt orother similar porous material'toserve as a filter and thus prevent theentrance of any solid particles into the tube of the hypodermic needle 0which is screwed onto the syringe in the usual manner. For filling thesyringe the cap a may be removed, and the liquid may then be poured intothe inverted syringe.

Connected with the upper end of the body of the syringe is a resistancehandle d, shown in Figs. 1 and 2 as being soldered or other-- Wisepermanently attached to a collar d fitting around the upper end of thebody of the syringe and held in place by means of a sleeve e which isfitted to turn freely on the body A and is partly threaded to engage theinside threaded portion of the said collar, a small flange a on the bodyA holding the sleeve and collar in place when the two are screwedtogether.

F denotes a piston rod andfthe piston carried thereby. The piston rod Fis preferably provided with a series of annular ratchet notches f.Connected to the rear portion d of the handle (1, by the link h, is ahand lever'i provided with apawl i for engagement with the notches f ofthe piston rod F,a spring 2' bearing upon the said pawl for the purposeof holding it in engagement with the notches f of the piston rod. Thelink his provided with a block it which is rigid or integral therewithand which serves as a bearing to steady the piston rod against the pushof the pawl '5'. This. block h also prevents the said pawl from catchingin the notches of the piston rod when the latter is lifted or drawn outfrom the body or barrel A, the lever 'i, by which said pawl is carried,assuming the position shown in dotted lines, Fig. 2, when the piston rodis being thus lifted or drawn out of the body or barrel A.

When it is desired to use the syringe the operator grasps the handle (1and lever 2' with one hand, while steadying the syringe with the other,and owing to the leverage afforded by the lever 1; the piston may beforced inward with considerable power, particularly with theco-operating aid of the relatively fixed resistance handle 01 which isgrasped with said lever 1'; and thus however tightly the piston may bepacked no difficulty is experienced in forcing the anesthaetic fluidinto the tissue of the gums; and as the syringe will be steadily heldwhen in operation the danger heretofore existing of breaking thedelicate needles used is largely or altogether avoided. Also owing tothe fact that the collar d to which the handle d is attached,and withwhich thehand lever dis also connected, is swiveled to the body of thesyringe, so as to turn freely with the sleeve e on said body, theseparts may be turned in any direction that may be desired to get at anyportion of the patients month which it may be news sary to reach. It is,however, not necessary, in carrying my invention into edect, that thepiston rod should be provided with ratchet notches or that the operatinglever 'i should be provided with a pawl for engagement therewith, as thehand lever may have a permaueutpivotal connection with the piston rod,asshown in Fig. 4, and the hand lever may be fixedly secured to the bodyof the syringe, instead of having a swiveled connection therewith asshown in Figs. 1 and 2, without departing from the essential features ofmy invention.

Having thus described my invention, I claim and desire to secure byLetters Paten 1. A hypodermic syringe provided at its upper end with aresistance handle and with an operating lever having means, betweenitsfulcrum point and operating end, for connection with the piston rod ofthe syringe.

2. The combination with the body or barrel of a hypodermic syringe, of aresistance handle having a swiveled connection with said body, anoperating lever provided between its fulcrum point and its operating endwith a spring pressed pawl, and a piston-rod carrying a piston andprovided with a series of annular ratchet notches to be engaged by saidpawl t9 force the said piston forward in the syringe.

3. The combination with the syringe having the piston rod F providedwith the pisstonf, of the handle (I, the lever 71, means for operativelyconnecting said lever with said piston rod, and one or more links 71.for connecting the fulcrum end of said lever with the portion (1 of saidhandle.

4. The combination with the syringe barrel or body A, of the piston-rodF provided with a series of ratchet 'notches, the resistance handleconnected with said barrel or body, the link It having the bearing blockor portion h resting against said piston rod, and the lever t jointed tosaid link and provided with a spring-pressed pawl to engage the notchesof said piston-rod.

5. The combination with the syringe body or barrel A, of the piston rodF provided with annular ratchet notches and carrying the piston f, ofthe collar d swivled to one end of said body A, the handle d secured tosaid collar, the lever '11 provided with a springpressed pawl forengagement with the notches of said rod, and the link it connecting thefulcrum end of said lever with the end d of said handle.

6. The combination with the syringe body A provided at its needle endwith a removable cap a carrying the hollow needle c, of a porous disk orfilter within said cap and serving to prevent particles of solid matterfrom entering the said hollow needle.

7. The combination with the syringe body or barrel A, of the removablecap a, the needle c removably attached to said cap, the packing ring ainclosed in said cap, and the por ous disk or plug b inserted in saidring.

In testimony whereof I aifix my signature in presence of two witnesses.

PHILIP B. LASKEY.

Witnesses:

FOSTER L. MARSHALL, WM. B. LASKEY.

